1. Field of the Invention
The present invention relates to a method for surface treatment of a metal base, and particularly to a method which involves at least two anodizing treatments of a metal base to give a surface of the metal base an anaglyphic decorative effect.
2. Related Art
Metals such as aluminum and titanium are becoming more widely used for producing cover structures of electronic devices such as laptop computers, personal digital assistants and mobile phones. Different methods for surface treatment of the metals have been developed to enhance the visual effect of the cover structures. A method for preparing decorative lacquered titanium-based articles is disclosed in U.S. Pat. No. 5,215,605. The method comprises numerous steps including: (a) heating a base of titanium to between 900xc2x0 C. and 1300xc2x0 C. in vacuum to grow crystal grains on a surface of the base; and (b) etching the surface of the base with an etchant.
Conventional methods, such as the method described above, for obtaining an anaglyphic decorative effect on a metal article are laborious and costly.
An improved method for surface treatment of a metal article which can overcome the above-mentioned problems is desired.
An object of the present invention is to provide a simple method for surface treatment of a metal base to give the surface an anaglyphic decorative effect.
Another object of the present invention is to provide a metal base having an anaglyphic decorative effect.
To achieve the above-mentioned objects, a method for surface treatment of a metal base in accordance with the present invention comprises the steps of: (a) anodizing the base to obtain a first layer of oxidation film on a surface of the base; (b) removing or covering a first area of the oxidation film; and (c) anodizing the base to obtain a second layer of oxidation film. A second area of the oxidation film is thus formed on the base which is different from the first area of the oxidation film. The second area is either higher or lower than the first area, therefore an anaglyphic decorative effect is obtained on the surface of the base.
Other objects, advantages and novel features of the present invention will be drawn from the following detailed description of preferred embodiments of the present invention.